Exercise and Sun

Sun exposure during exercise could be particularly hazardous to the skin. Strenuous physical exertion produces oxidative stress that depletes the skin of antioxidants, making it more vulnerable to sun damage, says dermatologist Alexa Patzelt of the Charité University Hospital in Berlin. She and her colleagues found that volunteers who did 30 minutes of moderate- to high-intensity cycling or running indoors decreased the antioxidant levels of their skin by 2 to 40 percent. (This didn't occur with "unhurried" physical activity, Patzelt adds.) Besides avoiding outdoor workouts when the sun is strong, Patzelt advises wearing sun-protective clothing while exercising outside and applying a high-SPF sunscreen containing antioxidants every two hours (or more often if sunscreen is wiped off during exercise). Eating a diet rich in fruits and vegetables also increases antioxidants in the skin; supplements may not be as safe or reliable, she cautions.